Baffle for heat exchange tubes



May 25? 1937-' J. c. wooDsoN 2,081,612

BAFFLE FOR HEAT EXCHANGE TUBES Filed Nov. 13, 1936 INVENTOR g V JCI mes 0. Woodson Patented May 25, 1937 .PATENT oFricE i 2,081,612 amm Foa naar EXCHANGE 'runas llames C. Woodson, Cleveland, Ohio, assignor to Lee Wilson, Cleveland, Ohio Application November 13, 1936, Serial No. 110,723

9 Claims.

This invention relates to a baiiie for heatexchange tubesi such as those employed in annealing furnaces of the cover type, such as that described and claimed in Wilson Patent No.

Bafiles disposed in heat-exchangetubes such as those of the aforementioned patent have several functions, viz., to restrict the combustion generally to the lower portion of the tube where it is desired that most of the heat be absorbed and radiated to the work; to break up the central core oi hot combustion gases which would be formed in the absence of bales; and to cause such gases to scrub the inner surfaces of the tubes more thoroughly whereby to cause the absorption by the tubes of the maximum amount of heat from the gases. The severity of the operating conditions within the heat-exchange tubes and the particular conformation of the tubes themselves make proper baiing of the hot combustion gases a serious problem. The results of earlier efforts along this line are disclosed in -copending applications Serial Nos. 49,078 and 74,958 and, with the experience gained in the use of the baffles there shown, I have invented a novel form of baffle which affords a highly satisfactory solution to a somewhat perplexing problem.

. In accordance with my invention, I utilize a plurality of refractory blocks as baiies. The blocks are assembled in the form of a chain on metallic links which may be readilylr attached to and separated from each other. The bocks are shaped to direct the combustion gases toward the inner surface of the heat-exchange tubes, without objectionably interfering with the ilow of gases longitudinally of the tube. The metallic links extending axially of the blocks are protected to a large extent from the combustion gases whereby rapid deterioration thereof, because of the high temperature of the gases, is avoided.

The accompanying drawing illustrates a preferred embodiment of the invention and is to be read in connection with the following detailed description. ln the drawing,

Fig. 1 is a partial transverse section through the side wall of a cover-type furnace and a heat-exchange tube mounted therein;

Fig. 2 is a partial elevation of a bale;

Fig. 3 is a sectional view along the line III-III of Fig- 2;

Fig. 4 is a plan view of one of the baille blocks;

and

Fig. 5 is a section along the line V-V of Fig. 2.

(Cl. 13B-38) -As an example of the applications which may be made oi the invention, I show a cover-type furnace l comprising side walls Il, end walls i2 and a roof I3 composed ci refractory material assembled within a structural frame I4. The cover il! is open at the bottom and is adapted to be disposed on a charge-receiving base (not shown).

Heat-exchange tubes l5 are mounted on the side walls of the cover i0. The construction and arrangement of these tubes are more particularly described and claimed in my copending application Serial No. '74,958 above referred to.

A burner l5 is mounted in the lowerend of each tube for delivering hot combustion gases thereto. A bale i1 is suspended in each tube from the 1 upper end thereof by means tc be described later.

The baille i1 comprises a plurality of metallic links i9 detachably connected and refractory blocks disposed on certain of the links as shown in Fig. 1. The blocks are somewhat cruciform in shape, as shown in Fig. 4, and have a central slot 2l therethrough to admit the links I9. 'I'he ends of the blocks are somewhat tapered, as at 22, in a manner which can perhaps be best described by stating that the corners are knocked off.

The links i9 each have a head 28 at one endand an eye 24% at the other end. The eye has a large portion and a reduced portion whereby the head` may readily be inserted through the former andtemporarily locked by movement of the neck finto the reduced portion of the eye.

At the bottomof the bafie, a special block 26 is suspended on a short link 21 by a refractory pin 28. The pin has a peripheral groove 29 adapted to receive the edge of .the eye t@ in the link 2l to prevent movement of the pin from the block while the latter is suspended. The block 2t is tapered toward its lower end to divert the ascending stream of combustion gases substan- 40 tially uniformly thereabout.

A hook link ita is adapted to engage the upper edge of the tube Iii. The topmcst link It is secured to the link 19a by the same head and eye arrangement which connects theA links i9 to each 45 other.

The baffle I7 may conveniently be assembled apart from the tube i5 and then lowered thereinto. The shape of the blocks is such as to cause 50 thorough scrubbing of the inner wall of the tube by the gases without offering excessive resistance to the flow thereof. The metallic links are protected from direct contact with the combustion gases to a large extent, and particularly the bot- 55 tom link 2l which does not extend through the block 26 but terminates short of the lower end thereof. 'I'he blocks 20 and 28 are preferably composed of porcelain as is also the pin 28. The

links I9 and 2l are preferably cast from a heat-l of the head from the eye of the link through which it is inserted. The baille shown being of the nature of a chain, it is ilexible in al1 directions and no particular pains need be taken when inserting it in a tube. A baffle of the type shown is particularly effective in conning combustion largely to the lower portion of the tube I5, as well as in breaking up the central core of combustion gases which would be formed in the absence of a baille, and thus insures intimate contactl of all the combustion gases with the tube wall.

Although I have illustrated and described but one preferred embodiment of the invention, it will be apparent that changes in the exact construction disclosed may be made without varying the principle thereof.

I claim:

1. A baille for heat-exchange tubes comprising a plurality of refractory blocks, an axial hole through each block. a metallic link positioned in the hole in each block, said links having a head at one end and an eye at .the other adapted to receive the head of an adjacent link, whereby the links may be assembled in a chain with the blocks strung on the links in the manner of beads.

2. The baille defined by claim 1 characterized by said blocks having their corners knocked oif. 3. A chain baule adapted to be suspended in a heat-exchange tube comprising a plurality of bar linkageach having a head at one 'end andan eye at the other. the head of each link being inserted through the eye of the adjacent link, and a refractory block for each link, the block having an axial hol'e through which the link extends.

4. A chain baille deilned by claim 3 characterized by the block on each link resting on the head of the link below.

5. The chain baille dened by claim 3 characterized by the bottom link of the chain having its block securedthereto by a refractory pin.

6. The chain baille defined by claim 3 characterized by the bottom link extending into its block but terminating short of the lower end of the block.

7. A chain baille adapted to be suspended in a heat-exchange tube comprising a plurality of refractory blocks, each block having an axial hole therethrough, and a link extending through said hole, the links Ioi.' adjacent blocks being connectible to form a chain.

8. The chain baille defined by claim 7 characterized by said links having means separably connecting them.

9. A baille for heat-exchange tubes comprising a plurality of refractory baille members, slots extending axially through said members, iiat bar links havingv cooperating eyesand heads disposed in said slots and assembled together to form a chain.

JAMES c. WooDasoN.l 

